code: def _test_sync(cls):
      from ignite.distributed.utils import _SerialModel, _set_model
  
      _set_model(_SerialModel())
  
      sync()
  
      from ignite.distributed.utils import _model
  
      assert isinstance(_model, cls), f"{type(_model)} vs {cls}"
  
file_path: ignite/tests/ignite/distributed/utils/__init__.py
imports: import pytest
  import torch
  import torch.distributed
  import ignite.distributed
  from ignite.distributed.utils import sync
  from ignite.engine import Engine, Events
label_desc: Use image node_id 3 for calling a global function with example usage: _test_sync(cls) without return types